The Oracle Server X5-2 Service Manual provides product-specific information about troubleshooting problems; refer to Troubleshooting and Diagnostics in Oracle Server X5-2 Service Manual.
The Oracle x86 Servers Diagnostics, Applications, and Utilities Guide for Servers with Oracle ILOM 3.1 and Oracle ILOM 3.2.x provides information about a wide variety of tools available for Oracle's x86 servers. Go to http://www.oracle.com/goto/x86admindiag/docs.
Knowledge articles, white papers, and product updates are available through the Oracle Support portal at https://support.oracle.com.